682 



FAMILY XXXIV. — HETEROCERIDiE. 



Macronychus glabratus Say, blackish, antennae pale reddish- 

 brown, seventh interval carinate, length 3-3.5 mm., is known from 

 Pennsylvania. 



Ancyronyx variegatus Germ., black, elytra with yellow stripes, 

 length 3-3.5 mm., is recorded from the Middle States and Ten- 

 nessee. 



Family XXXIV. HETEBOCERIDiE. 



The Variegated Mud-loving Beetles. 



To this family belong a small number of subdepressed, oblong or 

 elongate, semi-aquatic beetles which live in galleries which they ex- 

 cavate in the sand or mud along the borders of streams and lakes. 

 When disturbed they run from their galleries and take night, as do 

 certain species of Bembidium, They are of a brownish or blackish 

 color, usually variegated with undulated bands or spots of dull yel- 

 low, and have the body very finely punctate and densely clothed 

 with short, silky pubescence. From the Parnida?, with which they 

 were formerly grouped, they differ mainly in having the front and 

 middle tibiae widened and armed with spines on the outer edge, thus 

 enabling them to burrow in the wet sand which they and their larvas 

 inhabit. 



The name Heterocerus, that of the typicai and only genus, comes 

 from two Greek words meaning '''different" and "horn," and was 

 so given from the irregularity of the 11-jointed antennae, joints 5 to 

 11 of which form an oblong, serrate club (Fig. 4, No. 9). 



In addition to the characters mentioned, the members of the 

 family have the mentum large, oblong, deeply emarginate in front ; 

 thorax transverse with rounded angles ; presternum lobed in front, 

 acute behind; mesosternum very short, deeply emarginate; elytra 

 entirely covering the abdomen, which is composed of five nearly 

 equal ventral segments, the fifth only being movable, the others 

 connate; front coxa? oval, transverse, the cavities widely open be- 

 hind; tarsi 4- jointed, the second and third joints shorter than the 

 others. 



The only paper treating of the North American species is that bj 

 Horn,— ' ' The Species of Heterocerus of Boreal America," in 

 Trans. Amer. Entom. Soc, XVII, 1890, 1-16, pi. I. 



I. Heterocerus Bosc. 1792. (Gr., "different + horn. ") 



In the paper above cited, Dr. Horn reduced the 1 6 species of the 

 genus listed by Henshaw to nine, and added two new ones. One of 

 the principal characters used by him in separating the species is the 



